Tolvaptan (kidney disease)

Tolvaptan (Jynarque) is used to slow the worsening of kidney function in certain patients with autosomal dominant polycystic kidney disease (ADPKD; a certain type of inherited kidney disease). Tolvaptan (Jynarque) is in a class of medications called vasopressin V₂ receptor antagonists. It works by increasing the amount of water released from the body as urine and decreases the growth of cysts in the kidneys. Removing fluid from the body and slowing the growth of cysts helps to slow the worsening of kidney function.

Tolvaptan is also available as a tablet (Samsca) to treat low blood levels of sodium in people who have heart failure or certain other conditions. This monograph only gives information about tolvaptan tablets (Jynarque) to slow the worsening of kidney function in patients with ADPKD. If you are using this medication to treat low levels of sodium in the blood, read the monograph entitled tolvaptan (low blood sodium).

Tolvaptan (Jynarque) comes as a tablet to take by mouth. It is usually taken twice a day, one tablet in the morning and one tablet 8 hours later, with or without food. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take tolvaptan (Jynarque) exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Your doctor will probably start you on a low dose of tolvaptan (Jynarque) and gradually increase your dose.

Your doctor may need to decrease your dose if you experience certain side effects. It is important for you to tell your doctor how you are feeling during your treatment.

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

Before taking tolvaptan (Jynarque),

• tell your doctor and pharmacist if you are allergic to tolvaptan (Jynarque, Samsca), any other medications, or any of the ingredients in tolvaptan tablets. Ask your pharmacist or check the Medication Guide for a list of the ingredients.

• tell your doctor if you are taking certain antifungals such as ketoconazole (Nizoral) or itraconazole (Sporanox); clarithromycin (Biaxin); or certain medications for HIV such as indinavir (Crixivan), lopinavir (Kaletra), nelfinavir (Viracept), ritonavir (Norvir), or saquinavir (Invirase); conivaptan (Vaprisol); or nefazodone. Your doctor may tell you not to take tolvaptan (Jynarque) if you are taking one or more of these medications.

• tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: atorvastatin (Lipitor, in Caduet), bosentan (Tracleer), desmopressin (dDAVP, Minirin, Noctiva), digoxin (Lanoxin), fluconazole (Diflucan); furosemide (Lasix), glyburide (Diabeta, Glynase), lovastatin (Altoprev), methotrexate (Otrexup, Rasuvo, Trexall, Xatmep), nateglinide (Starlix), pravastatin (Pravachol), repaglinide (Prandin), rifampin (Rifadin, Rifater, Rimactane), rosuvastatin (Crestor), and simvastatin (Zocor, in Vytorin). Your doctor may need to change the doses of your medications or monitor you carefully for side effects. Many other medications may also interact with tolvaptan (Jynarque), so be sure to tell your doctor about all the medications you are taking, even those that do not appear on this list.

• tell your doctor if you have any of the conditions mentioned in the IMPORTANT WARNING section, if you have or have ever had a high level of sodium in your blood, if you have difficulty urinating or are unable to urinate, if you have had severe vomiting or diarrhea or think you may be dehydrated, or if you are unable to notice that you are thirsty. Your doctor may tell you not to take tolvaptan (Jynarque).

• tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. If you become pregnant while taking tolvaptan (Jynarque), call your doctor. You should not breastfeed while you are taking tolvaptan (Jynarque).

You will need to drink enough water while you are taking tolvaptan (Jynarque) so you do not become thirsty or dehydrated.

Do not eat grapefruit or drink grapefruit juice while taking this medication.

Skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

• Tolvaptan (Jynarque) may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

  • thirst

  • dry mouth

  • frequent, excessive urination

  • heartburn

  • decreased appetite

• Some side effects can be serious. If you experience any of these symptoms or those listed in the IMPORTANT WARNING section, call your doctor immediately:

  • diarrhea

  • inability to drink normally

  • dizziness

  • faintness

  • decreased urination

  • weakness

  • drowsiness

  • confusion

  • weight loss

  • rapid or pounding heartbeats

  • swelling of the face, throat, tongue, lips, eyes, hands, feet, ankles, or lower legs

  • hoarseness

  • hives

• Tolvaptan (Jynarque) may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

• If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.

Symptoms of overdose may include:

• excessive urination

• excessive thirst

• dizziness

• faintness

Keep all appointments with your doctor and the laboratory. Your doctor may order certain lab tests to check your body's response to tolvaptan (Jynarque).

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.